How a PHP class file accesses variables in other files

How a PHP class file accesses variables in other files
I declare 2 files, a class file (123.class.php), an ordinary file (index.php, code below), 123.class.php How to get the $ABC value in the index.php file (in the class file directly include, Not available)

The 123.class.php code is as follows:

PHP Code

index.php Code:

PHP Code

Instantiate code:

$ABC =new A123;
$ABC->index ();

------Solution--------------------
Include (' index.php ');
Class a123{
Public Function index{
Global $aa, $BB; or include (' index.php ');
Echo $aa;
Echo $BB;
}
}
------Solution--------------------
Global

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